Fluid waste collection and disposal system and method

ABSTRACT

A system and method of collecting and disposing of fluid during a medical procedure. Fluid is drawn from a fluid source into a first reservoir in communication with a vacuum source. The fluid passes through an open fluid transfer valve into a second reservoir in communication with the vacuum source. While the fluid continues to be drawn into the first reservoir, the fluid transfer valve is closed after a predetermined volume of the fluid passes into the second reservoir. The fluid collected in the second reservoir is measured and evacuated from the second reservoir. The fluid transfer valve is opened and the steps are repeated until the medical procedure is completed while the first reservoir remains in uninterrupted communication with the vacuum source during the medical procedure such that fluid is capable of continuing to be drawn into the first reservoir without interruption.

BACKGROUND

Systems for collecting and disposing of bodily fluids and other fluidsthat are aspirated from a patient during surgical procedures are wellknown. Conventional fluid waste collection systems typically use sometype of container or canister into which the aspirated fluids arecollected. As the fluid collection canisters become filled during thecourse of a surgical procedure, the filled canisters are replaced withempty canisters. Depending on the volume of the canisters and the amountof fluid being collected, the surgical procedure may have to beinterrupted to replace a filled canister with an empty canister.

It should be appreciated that the aspirated fluids may be contaminatedwith pathogens, such as HIV, HPV, Hepatitis, MRSA and other infectiousagents. During the surgical procedure and/or after the surgicalprocedure is completed, the fluid filled canisters are typically cartedfrom the operating room to a central collection location for disposalor, alternatively, the canisters may be emptied, cleaned, and re-used.Accordingly, handling of fluid collection canisters by hospitalpersonnel creates a risk that the handlers may come into contact withthe contaminated fluids contained in the canisters due to spillage,leaks or splashing while carrying, emptying or cleaning the canisters.

In an effort to minimize exposure to pathogens in the aspirated fluid,the canisters may be partially pre-filled with a disinfectant to destroyany pathogens as the fluid enters the canisters. Alternativelysolidifying agents or coagulants may be added to the canisters tominimize the potential for spillage, splashing and leakage. However,such additives increase the disposal costs because the canisters mustthen be treated as hazardous waste and must be incinerated or deliveredto a landfill. Furthermore, there is also the additional labor andassociated costs with having to purchase, store, and handle thecanisters themselves. In any event, whether disinfectants or solidifiersare added, there remains a risk that handlers of the canisters willstill come into contact with the fluid waste.

In an attempt to overcome the risk of exposure to pathogens and theadditional costs and labor associated with the use of canisters tocollect fluid waste, systems have been developed to collect the fluidwaste in reservoirs which can be drained directly into the facility'ssewer system. However, such systems operate in a manner very similar tothe canister systems (apart from having to handle the canisters).Specifically, such systems utilize redundant reservoirs and piping sothat when the first reservoir is filled, the operator has to manuallydisconnect the suction hose from the first reservoir and re-connect thesuction hoses to the second reservoir which presents the sameundesirable interruption of the medical procedure as when using acanister-type collection system.

In an attempt to minimize the interruption of the medical procedure,others have attempted to automate the process using redundant systems,with each system having its own reservoir, vacuum line, drain pipe,fluid level sensor and associated valving. In use, the first reservoiris under negative pressure and collects the fluid. When the firstreservoir reaches a predetermined fill level as detected by the firstfluid level sensor, the system is programmed to switch the negativepressure from the first reservoir to the second reservoir, such that thesecond reservoir begins to collect the fluid while the fluid in thefirst reservoir is drained. This automatic switching between filling anddraining the redundant systems is repeated until the medical procedureis completed. While the switching between reservoirs is much quickerusing the automated process than doing so manually, and while thecapacity to collect fluid is theoretically unlimited, such automaticswitching systems nevertheless still cause an undesirable briefinterruption of the suction while the system switches between thereservoirs.

Accordingly, there remains a need for an efficient system for collectingand disposing of aspirated fluid waste from medical procedures, whicheliminates the need for handling of canisters to avoid the potentialrisk of exposure to pathogens, which has an unlimited capacity, andwhich avoids any interruption of suction during the medical procedure.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of one embodiment of a housing andmanifold for a fluid waste collection and disposal system.

FIG. 2 is a bottom perspective view of the housing of the fluid wastecollection and disposal system of FIG. 1.

FIGS. 3A and 3B are enlarged perspective views of the manifold of FIG. 1showing the cleaning solution hanger in an attachment position and in aninverted use position.

FIG. 4 illustrates an embodiment of a touch screen display of the fluidwaste collection and disposal system of FIG. 1.

FIGS. 5-9 schematically illustrate alternative embodiments of the fluidwaste collection and disposal system wherein the fluid reservoirs areshown in stacked relation.

FIG. 10 schematically illustrates another embodiment of a fluid wastecollection and disposal system with the fluid reservoirs in aside-by-side relation.

FIGS. 11A-11D schematically illustrate the fluid waste collection anddisposal system of FIG. 5 showing various steps of using the system tocollect and dispose of fluid waste.

FIGS. 12A-12D schematically illustrate the fluid waste collection anddisposal system of FIG. 9 showing various steps of using the system tocollect and dispose of fluid waste.

FIGS. 13A-13E schematically illustrate the fluid waste collection anddisposal system of FIG. 5 showing various steps a process for cleaningthe system.

FIGS. 14A-14F schematically illustrate the fluid waste collection anddisposal system of FIG. 9 showing various steps of a process forcleaning the system.

DESCRIPTION

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIGS. 1and 2 are top and bottom perspective views, respectively, of anembodiment of a fluid waste collection and disposal system designatedgenerally by reference numeral 10. The system 10 is shown having ahousing 12 adapted for mounting on a wall or in a partially recessedfashion into a wall in the operating room or other facility in whichfluid aspiration procedures are performed. A mounting flange 14 isprovided for securing the housing to any suitable surface or structureusing appropriate fasteners. It should be appreciated, however, that thesystem 10 may be a free standing stationary or portable system.

The housing 12 includes a front panel 16 for access to the interior ofthe housing and the components therein (discussed later). The frontpanel 16 may include a lock 18 or other security mechanisms to preventunauthorized access to the interior of the housing 12. The front panel16 includes a touch screen display 20, a fluid viewing window 22, andone or more vacuum adjustment controllers 24. The vacuum adjustmentcontroller(s) 24, may be rotatable dials, push buttons, slide mechanismsor part of the touch screen display 20. As discussed in more detaillater, the front panel 16 also supports a manifold 30 comprisingplurality of suction ports to which suction hoses 80 are attached. Themanifold 30 may support a cleaning solution hanger (discussed later) forremovably receiving a cleaning solution bottle 28. One side panel of thehousing 12 may include a vacuum connection port 32, a power sourceconnection 34 and an on-off switch 36. The power source may be 24 VoltDC or any other suitable power source. A bottom panel of the housing 12may include a main drain port 38 and a secondary drain port 40. Itshould be appreciated that the particular location of the foregoingitems may vary depending on the configuration of the housing and thecomponents therein and where and how the system 10 is installed and/ormounted.

FIGS. 3A and 3B are enlarged perspective views of the manifold 30 ofFIG. 1. The manifold 30 includes outlet ports 302 which connect to thefluid inlet line 70. Each of the outlet ports 302 are in fluidcommunication with a pair of suction ports 304 to which the suctionhoses 80 attach as shown in FIG. 3A. It should be appreciated thatrather than connecting the suction hoses 80 to the suction ports 304directly, the suction hoses 80 may connect to a filter (not shown) whichthen connects to the suction ports 304. The manifold 30 also supports acleaning solution hanger 310, which includes outwardly projecting arms312 which support a block 314 rotatable about a pin 316. One end of theblock includes a threaded receptacle 318 (FIG. 3B) for threadablyreceiving a threaded end of a cleaning solution bottle 28. Afterthreading the bottle 28 to the block 314, the bottle 28 and block 314may be rotated such that the bottle 28 is inverted with respect to themanifold 30 as shown in FIG. 3B. Passages 320 (FIG. 3B) communicate thecleaning solution from the inverted bottle 28 through the block 314 andthrough nipples 322 on the opposite side of the block 314. Cleaningsolution tubes 324 are connected at one end to the nipples 322 on theblock 314 and are connected at the other end to nipples 326 on a door328 that is slidable as indicated by arrow 330. As shown in FIG. 3B,when the bottle 28 is inverted, the cleaning solution tubes 324 passthrough an opening 332 in the manifold 30. Also as shown in FIG. 3B,during the Cleaning Cycle Process (described later), the suction hoses80 (or filter, if used) are disconnected from the suction ports 304 anddoor 328 is moved to the closed position such that the door nipples 326are aligned with the suction ports 304. An o-ring may be provided on theunderside of the door 328 around the openings of the door nipples 326 toprovide a fluid-tight connection between the door nipples 326 and thesuction ports 304. A switch (not shown) may be provided in the hanger310 such that when the block 314 and bottle 28 are inverted, a signal isgenerated permitting the cleaning process to continue. It should beappreciated, that instead of using a manifold 30, one or more suctionports 304 may be provided in the face of the panel 16 which connect tothe fluid inlet line 70. In such an embodiment, the suction hoses 80(and/or filter) may be connected directly to the panel suction ports 304(see FIG. 10). Similarly, the cleaning solution tubes 324 may beconnected directly to the suction ports 304 after removal of the suctionhoses 80 from the panel suction ports 304.

The system 10 includes a programmable logic controller (“PLC”) (notshown) which interfaces with the touch screen display 20 and othercircuitry. The circuitry and associated programming for the PLC forproviding the features and performing the functions described below inconnection with the “Fluid Collection and Disposal Process” and“Cleaning Cycle Process” would be readily understood and recognized bythose skilled in the art and therefore further discussion on thecircuitry is not warranted. Rather than using a PLC and associatedcircuitry, it should be appreciated that solid state circuitry could beutilized which could further reduce the total size of system 10, ifdesired, as well as provide additional desired functionality.

In FIG. 4, an embodiment of a display screen is illustrated for thetouch screen display 20. As illustrated, the touch screen display 20includes a “Fluid Collected” indicator 200, a “System Run Time”indicator 202, a “Table Suction” indicator 204, a “Source Suction”indicator 206, a status/information indicator 208, and a plurality ofselectable operational functions, including a “Start Suction” selection210, a “Stop Suction” selection 212, a “Start Clean Cycle” selection214, a “Clear Values” selection 216 and an “Advanced Operations”selection 218. The Fluid Collected indicator 200 indicates the volume offluid collected (preferably in milliliters) since pressing the StartSuction selection 210. The System Run Time indicator 202 indicates thetime passed, preferably displayed in hours, minutes and seconds, sincepressing the Start Suction selection 210. The Table Suction indicator204, indicates the vacuum or negative pressure, preferably in inches ormm Hg, at the suction ports 304 which is controlled by the vacuum adjustcontroller 24 on the front panel 16. If multiple suctions ports 304 areprovided, a separate Table Suction indicator 204 may be provided toindicate the negative pressure at each suction port. The Source Suctiondisplay 206, indicates, the suction provided by the facility's vacuumsystem, preferably in inches or mm Hg, to which the vacuum port 32 isconnected. The status/information indicator 208 provides information tothe operator such as the current operation selection, system status orany alarm conditions.

FIGS. 5-10 schematically illustrate alternative embodiments of the fluidwaste collection and disposal system 10. In each of the embodiments, thesystem 10 includes first and second reservoirs 50, 52, a conduit 54,fluid transfer valve 56, a drain pipe 58, a fluid discharge mechanism59, a fluid sensor 60, a fluid inlet line 70, an inlet line valve 72, avacuum line 90, a vacuum line valve 92, an auxiliary line 100, anauxiliary line valve 102 and a recirculation line 150. In the differentembodiments, additional lines and valves or different combinationsthereof, cooperate to control air flow and/or fluid flow through thesystem 10 as described in detail later under the “Fluid Collection andDisposal Process”.

In each of the embodiments, the first reservoir 50 is fluidly connectedto the second reservoir 52 by the conduit 54. The fluid transfer valve56, is disposed along the conduit 54 to control the transfer ofcollected waste fluid from the first reservoir 50 to the secondreservoir 52 (discussed later). The fluid transfer valve 56 may be asolenoid or motor driven valve, a check valve or other suitable valve.The drain pipe 58 is connected to the second reservoir 52 through whichthe collected fluid waste is discharged from the second reservoir 52into a suitable drain or waste pipe (not shown) for disposal. The fluiddischarge mechanism 59 is disposed along the drain pipe 58 to controlthe discharge of the collected fluid waste from the second reservoir 52into the drain or waste pipe. The fluid discharge mechanism 59 may be anelectronically controllable valve, such as a solenoid or motor drivenvalve, or a check valve or other suitable valve. Alternatively, thefluid discharge mechanism 59 may comprise a pump or the combination of avalve and pump.

The fluid sensor 60 is disposed to detect the amount of fluid collectedfrom the patient or fluid source during the procedure. The fluid sensor60 may be a mechanical float-type sensor, such as a ball-float sensor,or the fluid sensor 60 may be an electronic sensor such as a capacitivesensor, an optic sensor, an ultrasonic sensor, a piezo-resistancesensor, or the fluid sensor 60 may be a mass/weight measuring sensor,such as a load cell or the fluid sensor 60 may be a flow sensor, such asa flow meter disposed in the fluid inlet line 70, or any other suitablesensor for detecting the volume, level or mass/weight of the fluidcollected from the fluid source during the procedure. In the embodimentof FIGS. 5-7, the fluid sensor 60 is shown as a ball-float sensordisposed within the second reservoir 52. In this embodiment, a ball 62floats up and down within a sensor tube 64 to activate switches (notshown) depending on the fluid level in the second reservoir 52. In theembodiment illustrated in FIG. 8, the fluid sensor 60, is shown ascomprising an electronic sensor. In this embodiment, the fluid sensor 60comprises a low level sensor 66 and a high level sensor 68 disposed inthe second reservoir 52. In the embodiment illustrated in FIG. 9, thefluid sensor 60 is shown as a load cell (designated by arrows) to detectthe mass/weight of the fluid in the first and second reservoirs. In theembodiment of FIG. 10, the fluid sensor 60 is shown as a flow meter todetect the volume of fluid passing through the fluid inlet line 70. Itshould be appreciated that if a load cell or other mass/weight measuringsensor is used, the reservoir supports within the housing, as well asthe conduit 54, drain pipe 58 and other components may need to beflexible so the mass/weight of the fluid can be accurately detected ordetermined.

The fluid inlet line 70 is fluidly connected at one end to the manifold30 and at its other end to the first reservoir 50. The inlet line valve72, such as a check valve, is positioned along the fluid inlet line 70.On the exterior of the housing 12, single use disposable suction hoses80 connect to the suction ports 304 in the manifold 30. Rather thanconnecting the suction hoses 80 directly to the suction ports 304, asingle use disposable filter 76 may be inserted into the suction ports304 and the suction hoses may be attached to the filter. An end effector(not shown) on the distal end of the suction hose 80, is used to suctionor aspirate the waste fluid from the patient.

The vacuum line 90 extends between a regulated vacuum source (not shown)and a vacuum port 94 of the first reservoir 50. Disposed along thevacuum line 90 is the regulator 91 and the electronically controllablevacuum line valve 92, such as a solenoid or motor driven valve. Theauxiliary line 100 branches off the vacuum line 90 and connects to anauxiliary port 104 of the second reservoir 52. Disposed along theauxiliary line 100 is the electronically controllable auxiliary linevalve 102, such as a solenoid or motor driven valve.

Recirculation lines 150 and an electronically controllable valve or oneor more recirculation pumps are provided for recirculating cleaningsolution during the “Cleaning Cycle Process” (described later).

The various embodiments illustrated in FIGS. 1-10 are hereinafterdescribed. In the embodiment of FIG. 5, the fluid transfer valve 56 andthe fluid discharge mechanism 59 comprise electronically controllablevalves as previously described. In addition to the components identifiedabove which are common among all the embodiments, the embodiment of FIG.5 also includes a vacuum assist line 110 connecting a vacuum assistsource (not shown) to the auxiliary line 100. Disposed along the vacuumassist line 110 is a an electronically controllable vacuum assist linevalve 112, such as a solenoid or motor driven valve. A vent line 120which vents to atmosphere also connects to the auxiliary line 100.Disposed along the vent line 120 is an electronically controllable ventline valve 122 such as a solenoid or motor driven valve. Additionally, apressure line 130 connects a pressure source, such as an air compressor(not shown) to the auxiliary line 100. Disposed along the pressure line130 is an electronically controllable pressure line valve 132 such as asolenoid or motor driven valve. Also in the embodiment of FIG. 5, therecirculation line 150 fluidly connects the first and second reservoirs50, 52 and an electronically controllable valve 152 is disposed alongthe recirculation line 150 to control the flow of cleaning solutionduring the Cleaning Cycle Process.

The embodiment of FIG. 6 is substantially the same as FIG. 5 except thatthe vacuum assist and associated vacuum assist line 110 and vacuumassist line valve 112 are eliminated.

The embodiment of FIG. 7 is likewise substantially similar to FIG. 5except that the vacuum assist and pressure source and associated lines110, 130 and valves 112, 132 are eliminated.

The embodiment of FIG. 8 is substantially the same as FIG. 5, exceptthat a recirculation pump 160 rather than the recirculation line valve152 is used to control the flow of cleaning solution during the CleaningCycle Process.

In the embodiment of FIG. 9, the fluid transfer valve 56 and fluiddischarge mechanism 59 comprise check valves. Additionally, the ventline 120 and associated vent line valve 122 are eliminated. Also in theembodiment of FIG. 9, separate recirculation lines 150 and separaterecirculation pumps 160 are used to control the flow of cleaningsolution during the Cleaning Cycle Process.

The embodiment of FIG. 10, is substantially the same as the embodimentof FIG. 5, except that the first and second reservoirs 50, 52 arearranged in a side-by-side relationship as opposed to a stackedrelationship.

Although not shown, corresponding embodiments to those of FIGS. 6-9 mayalso be utilized for the embodiment of FIG. 10 where the reservoirs 50,52 are arranged in the side-by-side relation. It should also beappreciated that the various components of the different embodimentsidentified above may be interchangeable among the embodiments andarranged in various configurations.

The first and second reservoirs 50, 52 and associated components in thevarious embodiments are constructed of suitable material of sufficientthickness to safely withstand the negative pressures typically used forthe vacuum systems of a medical facility, which typically are notgreater than 25 inches (635 mm) of mercury (Hg). Additionally, thereservoirs and associated components are preferably designed towithstand positive pressures of up to 20 psi. A suitable material forthe reservoirs may be transparent acrylic to allow the surgeon or othermedical personnel to view the aspirated fluid as it is collected forassessing its color or other characteristics. The first and secondreservoirs 50, 52 are preferably configured with sloped bottom walls topermit the complete drainage of collected waste fluid as discussed indetail later.

A light strip (not shown) which may comprise a plurality of white lightemitting diodes (LEDs) may be disposed behind the reservoirs 50, 52 toback-light the fluid in the reservoirs 50, 52 so it can be better viewedthrough the viewing window 22 in the front panel 16. If there is analarm condition, for example, if there is a leak or if the vacuum hasbeen interrupted due to fluid back-up, the LEDs are preferably caused tolight and flash to visually indicate an alarm condition. Under any alarmcondition, the PLC is preferably programmed to flash an error message onthe touch screen display 20.

Fluid Collection and Disposal Process

The process of collecting and disposing of the fluid waste using thesystem 10 is described below with reference to FIGS. 11A-11D whichcorrespond to the embodiment of FIG. 5. A brief description of theprocess for using the embodiments of FIGS. 6-8 and 10 follow thedescription of the embodiment of FIG. 5. A more detailed discussion ofthe fluid collection and disposal processes is provided for theembodiment of FIG. 9 with reference to FIGS. 12A-12D in view of thestructural and functional difference of the embodiment of FIG. 9 ascompared to the other embodiments.

With respect to all the embodiments, the system 10 may be powered on bypressing the on-off switch 36 to the “On” position or, alternatively, byactivating the touch screen 20. When the system 10 is powered on or isotherwise activated, the touch screen 20 preferably displays a “systemready” message in the status/information indicator 208 to indicate tothe operator that the system is ready for operation.

Fluid in Phase—FIG. 5 Embodiment

Referring to FIG. 11A, upon selecting the Start Suction operation 210,the initial “Fluid In” phase is initiated by the PLC generating a signalto open the electronically controllable fluid transfer valve 56 andauxiliary line valve 102 permitting communication of the vacuum sourcewith the second reservoir 52, and to the first reservoir 50 through theopen fluid transfer valve 56. The electronically controllable valves ofthe fluid discharge mechanism 59, vacuum assist line valve 112, the ventline valve 122 and the pressure line valve 132 are in the closedposition. Because the fluid transfer valve 56 is in the open position,it should be appreciated that the first and second reservoirs 50, 52will have the same negative pressure due to the air being evacuated (asindicated by the arrows) by the vacuum source. The negative pressureinside the reservoirs 50, 52 creates suction through the inlet line 70,which overcomes the bias of the normally closed inlet line check valve72, such that suction is provided to the suction ports 304 of themanifold 30.

The operator attaches the suction hose 80 to the suction ports 304. If afilter is used, the filter is connected to the suction ports 304 and thesuction hoses are connected to inlets on the filter. The distal end ofthe suction hose 80 includes an end effector (not shown) which typicallyincludes a regulator for controlling the amount of suction through theend effector. The operator may also adjust the amount of Table Suction204 using the vacuum adjust controller(s) 24. When the end effector onthe suction hose 80 is placed in contact with fluid, fluid is drawnthrough the suction hose 80 and into the first reservoir 50 and theninto the second reservoir 52 due to the fluid transfer valve 56 beingopen. The fluid entering the first and/or second reservoirs 50, 52 ispreferably visible through the window 22 in the front panel. As notedearlier, a light strip may be used to back-light the aspirated fluidentering in the reservoirs so it can be better viewed by the operator.

Relief and Measure Phase—FIG. 5 Embodiment

When the fluid level in the second reservoir 52 reaches a predeterminedfill level as detected by the fluid sensor 60 (e.g., by the ball float62 floating upward within the sensor tube 64 until the ball float 62triggers a switch in the sensor tube 64), a signal is generated whichbegins the “Relief and Measure” phase as illustrated in FIG. 11B. Thegenerated signal causes the PLC to open the vacuum line valve 92. Afterthe vacuum line valve 92 is opened, the PLC generates a signal to causethe fluid transfer valve 56 and the auxiliary line valve 102 to close,thereby isolating the second reservoir 52 from the vacuum source and thefirst reservoir 50. It should be appreciated that the first reservoirremains under negative pressure via the open vacuum line valve 92, suchthat communication of the vacuum source with the first reservoir is notinterrupted. When the fluid transfer valve 56 and auxiliary line valve102 are closed, a signal is generated to cause the PLC to open the ventline valve 122. Upon opening of the vent line valve 122, air enters thesecond reservoir 52 to relieving the negative pressure until it isbrought to atmospheric pressure. The volume of fluid in the secondreservoir 52 is then determined or otherwise measured and recorded bythe fluid measuring system 400 as described later.

Drain Phase—FIG. 5 Embodiment

Once the volume of the fluid in the second reservoir has been determinedand recorded, the “Drain” phase as illustrated in FIG. 11C is initiatedby the PLC generating a signal to cause the electronically controllablevalve of the fluid discharge mechanism 59 to open to permit the fluid tobegin to drain from the second reservoir 52 via gravity. To more rapidlyevacuate the fluid from the second reservoir 52, a signal may begenerated by the PLC to cause the vent line valve 122 to close and tocause the pressure line valve 132 to open. With the pressure line valve132 open, the pressure source, such as compressed air, enters the secondreservoir 52 to quickly and completely forcefully evacuate the fluidfrom the second reservoir 52 through the open valve of the fluiddischarge mechanism.

Second Reservoir Preparation Phase—FIG. 5 Embodiment

When the fluid in the second reservoir 52 has been evacuated (e.g., bythe ball float 62 within the sensor tube 64 dropping to trigger a switchat the bottom of the sensor tube 64 indicating that the fluid has beenevacuated), a signal is generated which begins the “Second ReservoirPreparation” phase as depicted in FIG. 11D. The generated signal causesthe PLC to close the valve of the fluid discharge mechanism 59 and toclose the pressure line valve 132, and to subsequently cause the vacuumassist line valve 112 to open. With the vacuum assist line valve 112open, the vacuum assist source draws air out of the second reservoir 52until the negative pressure in the second reservoir is substantiallyequal to the negative pressure in the first reservoir in communicationwith the vacuum source. Upon the equalization of the negative pressuresin the first and second reservoirs (which may be detected by a pressuretransducer or other suitable sensor), a signal is generated to cause thePLC to open the auxiliary line valve 102 and the fluid transfer valve 56to permit the fluid that has been collecting in the first reservoir 50to flow into the second reservoir 52 thereby repeating the processbeginning with the “Fluid In” phase as depicted in FIG. 11A, except thatthe vacuum line valve 92 remains open until the procedure is completedand Stop Suction 212 is selected on the touch pad. It should beappreciated that it is desirable to equalize the negative pressure inthe first and second reservoirs prior to opening the fluid transfervalve 56 to avoid or minimize a sudden drop or change in negativepressure in the first reservoir 50 (which could result in inconsistentsuction through the suction hose 80 at the procedure site) which mayoccur if there is a significant pressure differential between the firstand second reservoirs.

The “Fluid In”, “Relief and Measure”, “Drain” and “Second ReservoirPreparation” phases as depicted in FIGS. 11A-11D are repeated asnecessary until the medical procedure is completed.

The fluid collection and disposal process of the embodiment of FIG. 6 issubstantially similar to that of the embodiment of FIG. 5, except thatbecause the vacuum assist has been eliminated in the embodiment of FIG.6, after the fluid is drained from the second reservoir 52, the “SecondReservoir Preparation” phase is performed by the PLC generating a signalto open the auxiliary line valve 102 to equalize the negative pressurein the second reservoir 52 with the negative pressure in the firstreservoir 50 before the fluid transfer valve 56 is opened to beginrepeating the “Fluid In” phase.

Similarly, the fluid collection and disposal process of the embodimentof FIG. 7 is substantially similar to that of the embodiment of FIG. 6,except that because the vacuum assist and the pressure source have beeneliminated in the embodiment of FIG. 7, the fluid is drained from thesecond reservoir 52 during the “Drain” phase via gravity alone andtherefore the vent line valve 122 remains open until the fluid isdrained from the second reservoir. When the fluid is drained from thesecond reservoir 52, the PLC generates a signal to close the vent linevalve 122 and to initiate the “Second Reservoir Preparation” phase byopening the auxiliary line valve 102 to equalize the negative pressurein the second reservoir 52 with the negative pressure in the firstreservoir 50 before the fluid transfer valve 56 is opened to beginrepeating the “Fluid In” phase.

The fluid collection and disposal process of the embodiment of FIG. 8 isthe same as described in connection with FIGS. 11A-11D, but the CleaningCycle Process will vary as described later.

The fluid collection and disposal process of the embodiment of FIG. 10is substantially the same as that described in connection with theembodiment of FIG. 5 except that rather than utilizing a ball float typevolume sensor, the embodiment of FIG. 10 shows the fluid sensor 60 asbeing a flow meter rather than a float-type sensor.

Fluid in Phase—FIG. 9 Embodiment

Reference to FIGS. 12A-12D are made to describe the fluid collection anddisposal process for the embodiment of FIG. 9. Referring to FIG. 12A,upon selecting the Start Suction operation 210, the initial “Fluid In”phase is initiated by the PLC generating a signal to open the auxiliaryline valve 102 and/or the vacuum assist line valve 112 permittingcommunication of the vacuum source and/or vacuum assist source with thesecond reservoir 52 (as indicated by the arrows).

As previously identified, in the embodiment of FIG. 9, the fluidtransfer valve 56 and fluid discharge mechanism 59 comprise check valveswhich are not electronically controllable by the PLC. Because the fluidtransfer check valve 56 is biased in the normally closed position, thefluid transfer check valve 56 will remain closed until the negativepressure in the second reservoir sufficiently exceeds the negativepressure in the first reservoir to overcome the bias forcing the fluidtransfer check valve 56 to open. During the initial Fluid In phase, thevacuum line valve 92 remains closed and thus, the first reservoir is notin communication with the vacuum source. As a result, the fluid transfercheck valve 56 is forced to open when the auxiliary line valve 102and/or vacuum assist line valve 112 are opened because only the secondreservoir is in communication with the vacuum source and/or vacuumassist source.

With the fluid transfer check valve 56 open, the first reservoir is nowin communication with the vacuum source. The negative pressure insidethe reservoirs 50, 52 creates suction through the inlet line 70, whichovercomes the bias of the normally closed inlet line check valve 72,such that suction is provided to the suction ports 304 of the manifold30.

The operator attaches the suction hose 80 to the suction ports 304. If afilter is used, the filter is connected to the suction ports 304 and thesuction hoses are connected to inlets on the filter. The distal end ofthe suction hose 80 includes an end effector (not shown) which typicallyincludes a regulator for controlling the amount of suction through theend effector. The operator may also adjust the amount of Table Suction204 using the vacuum adjust controller(s) 24. When the end effector onthe suction hose 80 is placed in contact with fluid, fluid is drawnthrough the suction hose 80 and into the first reservoir 50 and theninto the second reservoir 52 due to the fluid transfer valve 56 beingopen. The fluid entering the first and/or second reservoirs 50, 52 ispreferably visible through the window 22 in the front panel. As notedearlier, a light strip may be used to back-light the aspirated fluidentering in the reservoirs so it can be better viewed by the operator.

Relief and Measure Phase—FIG. 9 Embodiment

When the fluid in the second reservoir 52 reaches a predetermined volumeor fill level (as detected by the load cell fluid sensor 60), a signalis generated which begins the “Relief and Measure” phase as illustratedin FIG. 12B. The generated signal causes the PLC to open the vacuum linevalve 92. After the vacuum line valve 92 is opened, the PLC generates asignal to close the auxiliary line valve 102 and/or vacuum assist linevalve 112 (depending on if both are provided and both are open) toisolate the second reservoir 52 from the vacuum source and/or vacuumassist source. With the second reservoir 52 isolated from the vacuumsource, the fluid transfer check valve 56 will return to its normallyclosed position due to the lack of greater negative pressure in thesecond reservoir sufficient to overcome the check valve bias, therebyisolating the second reservoir 52 from the first reservoir 50. It shouldbe appreciated that the first reservoir remains under negative pressurevia the open vacuum line valve 92, such that communication of the vacuumsource with the first reservoir is not interrupted. When the fluidtransfer valve 56 and auxiliary line valve 102 are closed, a signal isgenerated to cause the pressure line valve 132 to momentarily open torelieve the negative pressure in the second reservoir 52 until it isbrought to atmosphere. The mass/weight and/or volume of fluid in thesecond reservoir 52 is then determined or otherwise measured andrecorded by the fluid measuring system 400 as described later.

Drain Phase—FIG. 9 Embodiment

Once the mass and/or volume of the fluid in the second reservoir hasbeen determined and recorded, the “Drain” phase as illustrated in FIG.12C is initiated by the PLC generating a signal to cause the pressureline valve 132 to open to pressurize the second reservoir 52 sufficientto overcome the bias on the normally closed check valve of the fluiddischarge mechanism 59 causing it to open and forcefully evacuate thefluid from the second reservoir 52.

Second Reservoir Preparation Phase—FIG. 9 Embodiment

When the fluid in the second reservoir 52 has been evacuated (e.g., asdetected by the load cell), the “Second Reservoir Preparation” phase isinitiated as depicted in FIG. 12D by the PLC generating a signal tocause the pressure line valve 132 to close, and to cause the auxiliaryline valve 102 and/or vacuum assist line valve 112 to open to equalizethe negative pressure in the second reservoir with the negative pressureof the first reservoir. As the negative pressure in the second reservoirdecreases, the check valve of the fluid discharge mechanism 59 returnsto its normally closed position. The negative pressure in the secondreservoir is increased (or the negative pressure in the first reservoiris caused to slightly bleed off via the PLC generating a signal to causethe regulator 91 to open thereby reducing the negative pressure in thefirst reservoir) until there is a slight pressure differential betweenthe second reservoir and first reservoir sufficient to overcome the biasof the fluid transfer check valve 56 causing it to open, permitting thefluid being collected in the first reservoir to again flow into thesecond reservoir 52 thereby repeating the “Fluid In” phase as depictedin FIG. 12A, except that the vacuum line valve 92 remains open until theprocedure is completed and Stop Suction 212 is selected on the touchpad. The “Fluid In”, “Relief and Measure”, “Drain” and “Second ReservoirPreparation” phases as depicted in FIGS. 12A-12D are repeated asnecessary until the medical procedure is completed.

It should also be appreciated that in each of the embodiments of FIGS.5-10, the volume of the first reservoir 50 has sufficient capacity sothat it does not fill faster than is required to complete the “Reliefand Measure”, “Drain” and “Second Reservoir Preparation” phases. A fluidsensor may be disposed to monitor the fluid level, volume or mass in thefirst reservoir 50 similar to the fluid sensor 60 for monitoring thesecond reservoir to generate signals to trigger different phases of thefluid collection and disposal process and/or to trigger an emergencyshut-off of the vacuum line valve 92 if fluid in the first reservoir 50reaches a predetermined level to prevent fluid from being drawn into themain vacuum line 90 in the event of a malfunction.

It should be appreciated that, with each embodiment, because fluidcontinues to be drawn into the first reservoir 50 without interruptionwhile the fluid in the second reservoir 52 is being measured anddrained, the system 10 has an unlimited capacity and the suction throughthe suction hoses 80 remains continuous and substantially constant suchthat there is no interruption to the medical procedure.

Upon completion of the medical procedure, the operator selects the “StopSuction” operation 212 using the touch screen 20 thereby causing thevacuum line valve 92 (and the vacuum assist line valve 112 in the FIG.5A and FIG. 6 embodiments) to actuate and close-off the vacuum sourcefrom both reservoirs 50, 52.

Fluid Measuring System

A fluid measuring system 400 is provided to determine, record anddisplay the amount of waste fluid collected during the medicalprocedure. It is desirable for the surgical team to know the volume offluid loss from the patient during the procedure by comparing the volumeof the collected fluid in relation to the known quantities of saline orother fluids introduced into the patient during the procedure so as toensure that no excess fluid remains within the body cavity and to ensurethat excessive blood loss has not occurred; both being conditions thatmay place the patient at an increased post-operative risk.

The fluid measuring system 400 may comprise appropriate programming ofthe PLC to simply add the known liquid volume of the second reservoir 52(e.g., based on the point at which the ball float triggers the switch asin the embodiments of FIGS. 5-7 or at the position of the electronicsensor as shown in the embodiment of FIG. 8) to the previously recordedvalue stored in memory from the previous cycle(s). Alternatively, if aload cell is used for the fluid volume sensor 60, as illustrated in theembodiment of FIG. 9, the volume may be determined by programming thePLC to calculate the volume based on the mass/weight detected by theload cell multiplied by the specific gravity of the fluid beingcollected (within an acceptable range) and adding this value to thepreviously recorded values stored in memory from the previous cycles. Ifa load cell is used, the fluid volume may be determined while the secondreservoir 52 remains under negative pressure so the step of determiningthe volume could be performed prior to the venting/relief step describedabove. The running total of collected fluid volume is preferably causedto be displayed on the Fluid Collected indicator 200 of the display 20.Alternatively, a volume measuring pump or other suitable system may beused to measuring and record the fluid within the second reservoir or asthe fluid is being drained or evacuated during the “Drain” phase orwhile the fluid passes through the fluid inlet line 70 as illustrated inFIG. 10.

Cleaning Cycle Process

Upon pressing the Stop Suction operation after the procedure iscompleted, the operator may be prompted on the touch screen display 20to select the “Start Clean Cycle” operation 214. Upon pressing the StartClean Cycle operation, the operator may be instructed on the screendisplay 20 to remove the suction hose(s) 80 (and/or filter if used) fromthe suction port(s) 304 and to attach the cleaning solution bottle 28 tothe cleaning solution hanger assembly 310. It should be appreciated thatthe cleaning solution bottle 28 may be attached to the block 314 and thecleaning solution tubes 324 already attached to the nipples 322, 326 aspreviously described before the medical procedure begins. In which case,the screen display 20 may instruct the operator to invert the bottle 28as illustrated in FIG. 3B. Rather than utilizing bottles or bags, arefillable cleaning solution reservoir may be provided internal orexternal to the housing 12. The cleaning solution may be any solutionsuitable for cleaning and/or disinfecting bodily fluids that come intocontact with the internal surface areas of the system 10.

The Cleaning Cycle Process of the system 10 is described below withreference to FIGS. 13A-13E which correspond to the embodiment of FIG. 5.A brief description of the cleaning process for the embodiments of FIGS.6-8 and 10 follow the description of the embodiment of FIG. 5. A moredetailed discussion of the cleaning processes is provided for theembodiment of FIG. 9 with reference to FIGS. 14A-14F in view of thestructural and functional difference of the embodiment of FIG. 9 ascompared to the other embodiments.

Cleaning Solution in Phase—FIG. 5 Embodiment

When the Start Clean Cycle is initiated (whether by pressing the StartClean Cycle operation on the touch screen 20 or by triggering a switchupon inverting the bottle 28 as previously mentioned), the “CleaningSolution In” phase begins as depicted in FIG. 13A, by generating asignal to open the electronically controllable fluid transfer valve 56and auxiliary line valve 102 permitting communication of the vacuumsource with the second reservoir 52, and to the first reservoir 50through the open fluid transfer valve 56 (all other valves are closed).Because the fluid transfer valve 56 is in the open position, it shouldbe appreciated that the first and second reservoirs 50, 52 will havesubstantially the same negative pressure due to the air being evacuated(as indicated by the arrows) by the vacuum source. The negative pressureinside the reservoirs 50, 52 creates suction through the inlet line 70,which overcomes the bias of the normally closed inlet line check valve72, such that the cleaning solution is drawn into the first reservoir50, which then flows into the second reservoir through the open fluidtransfer valve 56.

Cleaning Solution Recirculation Phase—FIG. 5 Embodiment

When a predetermined amount of cleaning solution is drawn into thereservoirs 50, 52 (e.g., ⅓ to ½ of the volume of the cleaning solutionbottle), the “Cleaning Solution Recirculation” phase as depicted in FIG.13B is initiated by the PLC generating a signal to cause the auxiliaryline valve 102 to close and to cause the recirculation line valve 152and the pressure line valve 132 to open. Once the vacuum source is shutoff from the reservoirs 50, 52, the inlet line check valve 72automatically closes. The predetermined amount of cleaning solutionentering the reservoirs 50, 52 may be based on the fluid sensor 60 or atimer or other suitable measuring mechanism. The pressure from thepressure source forces the cleaning solution through the recirculationline 150 which splits toward each reservoir 50, 52 terminating innozzles 156. The nozzles 156 direct the cleaning solution to forcefullyspray the sidewalls of the reservoirs 50, 52.

Relief Phase—FIG. 5 Embodiment

After a predetermined time period, or when a pressure equilibrium isreached, the “Relief” phase as depicted in FIG. 13C is initiated by thePLC generating a signal to close the pressure line valve 132 and to openthe vent line valve 122 to release the pressure in the reservoirs 50,52.

Repeat Recirculation Phase—FIG. 5 Embodiment

After relieving the pressure in the reservoirs, the “RepeatRecirculation” phase as depicted in FIG. 13D is initiated to recirculatethe initial volume of cleaning solution, by the PLC generating a signalto close the vent line valve 122 and open the pressure line valve 132 toagain force the cleaning solution through the recirculation lines 150and through the nozzles 156. The “Relief” phase and “RepeatRecirculation” phase may be repeated several times.

Drain Cleaning Solution Phase—FIG. 5 Embodiment

After two or more recirculations of the initial volume of cleaningsolution, the “Drain Cleaning Solution” phase as depicted in FIG. 13E isinitiated by the PLC generating a signal to close the vent line valve122 and to open the drain valve 59 and pressure line valve 132 toevacuate the cleaning solution from the second reservoir. After theinitial volume of cleaning solution is drained, the “Cleaning SolutionIn”, “Cleaning Solution Recirculation”, “Relief”, “Repeat Recirculation”and “Drain Cleaning Solution” phases are repeated until the cleaningsolution bottle 28 is emptied and/or until the reservoirs are adequatelycleaned. Additional or alternative valving, piping and sequencing may bedesirable to facilitate thorough cleaning of the reservoirs andcomponents.

In the embodiment of FIG. 7 in which the pressure source is eliminated,a vacuum powered cleaning cycle may be used whereby, instead of usingthe pressure source to force the cleaning solution through therecirculation lines 150, a signal may be generated to cause the vacuumline valve 92 and auxiliary line valve 102 to open which will draw thecleaning solution through the recirculation lines 150 and nozzles 156 tospray the reservoir sidewalls.

In the embodiment of FIG. 8 in which the a recirculation pump 160 isused in place of the recirculation line valve 152, the process will besubstantially the same as described above in connection with theembodiment of FIG. 5, except that instead of generating a signal to openthe recirculation line valve and the pressure line valve 132 to forcethe cleaning solution through the recirculation lines 150, a signal isgenerated to initiate the recirculation pump 160 during the respectivephases to pump the cleaning solution through the recirculation lines150.

Cleaning Solution into Second Reservoir Phase—FIG. 9 Embodiment

Reference to FIGS. 14A-14F are made to describe the Cleaning CycleProcess for the embodiment of FIG. 9. As previously identified, in theembodiment of FIG. 9, the fluid transfer valve 56 and fluid dischargemechanism 59 comprise check valves which are not electronicallycontrollable by the PLC.

When the Start Clean Cycle is initiated (whether by pressing the StartClean Cycle operation on the touch screen 20 or by triggering a switchupon inverting the bottle 28 as previously mentioned), the “CleaningSolution Into Second Reservoir” phase begins as depicted in FIG. 14A, bygenerating a signal to cause the auxiliary line valve 102 and/or thevacuum assist line valve 112 to open (all other valves, including thevacuum line valve 92, are closed). As previously described in connectionwith FIG. 12A, because the vacuum line valve 92 is closed, the bias ofthe fluid transfer check valve 56 is overcome and is forced to openbecause only the second reservoir is in communication with the vacuumsource and/or vacuum assist source. With the fluid transfer check valve56 open, the first reservoir is now in communication with the vacuumsource and the negative pressure inside the reservoirs 50, 52 createssuction through the inlet line 70, which overcomes the bias of thenormally closed inlet line check valve 72, permitting the cleaningsolution to begin flowing into the first reservoir.

Cleaning Solution into First Reservoir Phase—FIG. 9 Embodiment

When a predetermined amount of cleaning solution is drawn into thesecond reservoir 52 (e.g., ¼ of the volume of the cleaning solutionbottle) as detected by the fluid sensor 60 for the second reservoir (orbased on time, or based on a flow meter or other means), the “CleaningSolution into First Reservoir” phase as depicted in FIG. 14B isinitiated by the PLC generating a signal to cause the auxiliary linevalve 102 (and the vacuum assist line valve 112, if provided and open)to close. Once the vacuum source is shut off from the second reservoir52, the fluid transfer check valve 56 closes. The PLC then generates asignal to cause the vacuum line valve 92 to open which causes apredetermined amount of cleaning solution to be drawn into the firstreservoir 50 (e.g., ¼ of the volume of the cleaning solution bottle) asdetected by the fluid sensor 60 for the first reservoir (or based ontime, or based on a flow meter or other means), at which point a signalis generated by the PLC to close the vacuum line valve 92, which causesthe inlet line valve 72 to close, preventing any additional cleaningsolution from entering the first reservoir 50.

Relief Phase—FIG. 9 Embodiment

After both the first and second reservoirs have the predetermined amountof cleaning solution is drawn into the reservoirs 50, 52 (e.g., ⅓ to ½of the volume of the cleaning solution bottle), the “Relief” phase asdepicted in FIG. 14C is initiated by the PLC generating a signal toclose the regulator 91 and to open the pressure line valve 132, theauxiliary line valve 102 and the vacuum line valve 92, permitting air toenter and relieve the negative pressure in both reservoirs 50, 52.Alternatively, rather than opening the auxiliary line valve, it mayremain closed and the PLC may generate a signal to cause the regulator91 to bleed to atmosphere and to opening the vacuum line valve therebyrelieving the negative pressure in the first reservoir.

Cleaning Solution Recirculation Phase—FIG. 9 Embodiment

Once the reservoirs are brought to atmosphere, the “Cleaning SolutionRecirculation” phase as depicted in FIG. 14D is initiated by the PLCgenerating a signal to actuate the recirculation pumps 160 which pumpsthe cleaning solution through the respective recirculation lines 150 andback into the respective reservoirs 50, 52 for a predetermined period oftime. The nozzles 156 direct the cleaning solution to forcefully spraythe sidewalls of the reservoirs 50, 52.

First Reservoir Drain Phase—FIG. 9 Embodiment

After a predetermined period of time of operating the recirculatingpumps 160 to recirculate the initial volume of cleaning solution, the“First Reservoir Drain” phase as depicted in FIG. 14E is initiated bygenerating a signal to stop the recirculation pumps 160 and to open theauxiliary line valve 102 to bring the second reservoir to a negativepressure such that the bias of the fluid transfer check valve 56 isovercome and is forced to open, permitting the cleaning solution fromthe first reservoir 50 to flow or be drawn into the second reservoir 52.

Drain Cleaning Solution Phase—FIG. 9 Embodiment

When the cleaning solution in the first reservoir is drained (asdetected by the load cells of the fluid sensor 60 on the firstreservoir), the “Drain Cleaning Solution” phase as depicted in 14F isinitiated by the PLC generating a signal to close the auxiliary linevalve 102 and to open the pressure line valve 132. As air flows into thesecond reservoir, the bias of the check valve of the fluid dischargemechanism 59 is overcome, and the cleaning solution is evacuated fromthe second reservoir. Once the load cell of the fluid sensor on thesecond reservoir detects that the cleaning solution has been completelyevacuated, the PLC generates a signal to repeat the “Cleaning SolutionIn”, “Cleaning Solution Recirculation”, and “Drain Cleaning Solution”phases until the cleaning solution bottle 28 is emptied and/or until thereservoirs are adequately cleaned.

The system 10 may incorporate a radio frequency identification (RFID)transceiver (not shown) which communicates with an RFID tagged cleaningsolution bottle or bag 28 to ensure compliance with proper cleaningpractices and warranty provisions. For example, the PLC of the system 10may be programmed to prevent the “Suction Start” operation from beingperformed unless the system had previously performed a Clean Cycle usinga recognized RFID tagged product. The PLC may also be programmed torecognize a unique RFID tag only once, so the same bottle or bag 28cannot be refilled with a non-approved cleaner and then reused.Additionally the PLC may be programmed to accept only certain RFIDtagged cleaning solution products produced within a certain date rangeto ensure that the cleaning solution has not exceeded its shelf-life.

In yet another alternative embodiment, the cleaning solution (or aseparate sterilizing solution) may be disposed to be in fluidcommunication with the first reservoir 50 during the normal operation ofthe system instead of only during the cleaning cycle. Thecleaning/sterilizing solution may be provided in bottles or bags or aninternal or external refillable reservoir as previously described. ThePLC may be programmed to periodically and/or continuously dispense thecleaning/sterilizing solution into the first reservoir 50, via gravity,negative pressure or via a pump, at the same time as the aspirated fluidenters the first reservoir 50 to immediately destroy any pathogens andor accelerate the breakdown of the biological material in the aspiratedfluid before the fluid is discharged into the sanitary sewer.

The foregoing description is presented to enable one of ordinary skillin the art to make and use the invention and is provided in the contextof a patent application and its requirements. Various modifications tothe preferred embodiment of the apparatus, and the general principlesand features of the system and methods described herein will be readilyapparent to those of skill in the art. Thus, the invention is not to belimited to the embodiments of the apparatus, system and methodsdescribed above and illustrated in the drawing figures, but is to beaccorded the widest scope consistent with the spirit and scope of theappended claims.

The invention claimed is:
 1. A method of continuously collecting anddisposing of fluid during a medical procedure without interruption andwithout limitation of the volume of the fluid capable of being collectedduring the medical procedure, the method comprising the steps of: (a)drawing fluid from a fluid source into a first reservoir incommunication with a vacuum source, the communication with the vacuumsource producing a substantially constant and continuous negativepressure in the first reservoir at all times during the medicalprocedure without interruption; (b) the fluid drawn into the firstreservoir passing through an open fluid transfer valve into a secondreservoir in communication with the vacuum source, the communicationwith the vacuum source producing a negative pressure in the secondreservoir, wherein the fluid transfer valve is a check valve biased in anormally closed position; (c) the fluid transfer valve closing after apredetermined volume of the fluid passes into the second reservoir,while at all times during the medical procedure, additional fluidcontinues to be drawn into the first reservoir; (d) measuring the fluidin the second reservoir; (e) evacuating the fluid from the secondreservoir through a discharge mechanism; (f) repeating steps (b) through(e) until the medical procedure is completed; whereby during all thesteps (a)-(f), the first reservoir remains in uninterruptedcommunication with the vacuum source such that fluid from the fluidsource is continuously drawn into the first reservoir withoutinterruption and without limitation of the volume of the fluid collectedduring the medical procedure until the medical procedure is complete. 2.The method of claim 1 further including the step of relieving thenegative pressure in the second reservoir prior to measuring the fluidin the second reservoir.
 3. The method of claim 2 wherein the step ofrelieving the negative pressure in the second reservoir includes ventingthe second reservoir to atmosphere.
 4. The method of claim 2 wherein thestep of relieving the negative pressure in the second reservoir includesproviding positive pressure to the second reservoir.
 5. The method ofclaim 1 wherein the step of evacuating the fluid from the secondreservoir includes pressurizing the second reservoir from a pressuresource.
 6. The method of claim 1 wherein the step of measuring the fluidcollected in the second reservoir includes determining a level of thefluid in the second reservoir.
 7. The method of claim 1 wherein the stepof measuring the fluid collected in the second reservoir includesdetermining a volume of the fluid in the second reservoir.
 8. The methodof claim 1 wherein the step of measuring the fluid collected in thesecond reservoir includes determining a weight of the fluid in thesecond reservoir.
 9. The method of claim 1 wherein the steps ofmeasuring and evacuating the fluid are performed by a metering pump. 10.The method of claim 1 wherein the check valve is opened from thenormally closed position by a negative pressure differential between thesecond reservoir and the first reservoir.
 11. The method of claim 1wherein the discharge mechanism is a drain valve.
 12. The method ofclaim 11 wherein the drain valve is an electronically controllablevalve.
 13. The method of claim 12 wherein a controller generates asignal to open and close the drain valve.
 14. The method of claim 11wherein the drain valve is a check valve biased in a normally closedposition.
 15. The method of claim 14 wherein the check valve is openedfrom the normally closed position by a positive pressure in the secondreservoir.
 16. The method of claim 1 wherein the discharge mechanism isa pump.
 17. The method of claim 1 further comprises a cleaning processesinitiated after completion of the medical procedure, the cleaningprocess comprising: (i) drawing cleaning solution from a cleaningsolution source into the first reservoir in communication with thevacuum source, the communication with the vacuum source producing anegative pressure in the first reservoir; (ii) the cleaning solutiondrawn into the first reservoir passing through the open fluid transfervalve into the second reservoir in communication with the vacuum source,the communication with the vacuum source producing a negative pressurein the second reservoir; (iii) after a predetermine volume of thecleaning solution enters the second reservoir, preventing communicationof the second reservoir with the vacuum source; (iv) circulating thecleaning solution through the first and second reservoirs; (v) drainingthe cleaning solution from the first and second reservoirs.
 18. Themethod of claim 17, wherein steps (i)-(v) are repeated at least once.19. The method of claim 17 wherein the cleaning solution source is abottle of cleaning solution.
 20. The method of claim 19 wherein step (i)is initiated by rotating the bottle from a first upright position to aninverted position.